Forecaster with Deep Learning¶

Recurrent Neural Networks (RNN) and Long Short-Term Memory (LSTM)¶

Recurrent Neural Networks (RNN) are a type of neural networks designed to process data that follows a sequential order. In conventional neural networks, such as feedforward networks, information flows in one direction, from input to output through hidden layers, without considering the sequential structure of the data. In contrast, RNNs maintain internal states or memories, which allow them to remember past information and use it to predict future data in the sequence.

The basic unit of an RNN is the recurrent cell. This cell takes two inputs: the current input and the previous hidden state. The hidden state can be understood as a "memory" that retains information from previous iterations. The current input and the previous hidden state are combined to calculate the current output and the new hidden state. This output is used as input for the next iteration, along with the next input in the data sequence.

Despite the advances that have been achieved with RNN architectures, they have limitations to capture long-term patterns. This is why variants such as Long Short-Term Memory (LSTM) and Gated Recurrent Units (GRU) have been developed, which address these problems and allow long-term information to be retained more effectively.

RNN diagram. Fuente: James, G., Witten, D., Hastie, T., & Tibshirani, R. (2013). An introduction to statistical learning (1st ed.) [PDF]. Springer.

Long Short-Term Memory (LSTM) neural networks are a specialized type of RNNs designed to overcome the limitations associated with capturing long-term temporal dependencies. Unlike traditional RNNs, LSTMs incorporate a more complex architecture, introducing memory units and gate mechanisms to improve information management over time.

Structure of LSTMs

LSTMs have a modular structure consisting of three fundamental gates: the forget gate, the input gate, and the output gate. These gates work together to regulate the flow of information through the memory unit, allowing for more precise control over what information to retain and what to forget.

• Forget Gate: Regulates how much information should be forgotten and how much should be retained, combining the current input and the previous output through a sigmoid function.

• Input Gate: Decides how much new information should be added to long-term memory.

• Output Gate: Determines how much information from the current memory will be used for the final output, combining the current input and memory information through a sigmoid function.

Diagram of the inputs and outputs of an LSTM. Fuente: codificandobits https://databasecamp.de/wp-content/uploads/lstm-architecture-1024x709.png.

💡 Tip

To learn more about forecasting with deep learning models visit our examples:

• Deep Learning for time series forecasting: Recurrent Neural Networks (RNN) and Long Short-Term Memory (LSTM).

Libraries¶

In [2]:

# Libraries
# ==============================================================================
import pandas as pd
import numpy as np
import tensorflow
import skforecast
import matplotlib.pyplot as plt
from skforecast.datasets import fetch_dataset
from skforecast.plot import set_dark_theme
from sklearn.preprocessing import MinMaxScaler
from skforecast.ForecasterRnn import ForecasterRnn
from skforecast.ForecasterRnn.utils import create_and_compile_model
from skforecast.model_selection_multiseries import backtesting_forecaster_multiseries
from tensorflow.keras.optimizers import Adam
from tensorflow.keras.losses import MeanSquaredError
from tensorflow.keras.callbacks import EarlyStopping
import warnings
warnings.filterwarnings('once')

print(f"skforecast version: {skforecast.__version__}")
print(f"tensorflow version: {tensorflow.__version__}")

# Libraries # ============================================================================== import pandas as pd import numpy as np import tensorflow import skforecast import matplotlib.pyplot as plt from skforecast.datasets import fetch_dataset from skforecast.plot import set_dark_theme from sklearn.preprocessing import MinMaxScaler from skforecast.ForecasterRnn import ForecasterRnn from skforecast.ForecasterRnn.utils import create_and_compile_model from skforecast.model_selection_multiseries import backtesting_forecaster_multiseries from tensorflow.keras.optimizers import Adam from tensorflow.keras.losses import MeanSquaredError from tensorflow.keras.callbacks import EarlyStopping import warnings warnings.filterwarnings('once') print(f"skforecast version: {skforecast.__version__}") print(f"tensorflow version: {tensorflow.__version__}")

skforecast version: 0.12.0
tensorflow version: 2.15.1

Data¶

In [3]:

# Data download
# ==============================================================================
air_quality = fetch_dataset(name="air_quality_valencia")

# Data preparation
# ==============================================================================
air_quality = air_quality.interpolate(method="linear")
air_quality = air_quality.sort_index()
air_quality.head()

# Data download # ============================================================================== air_quality = fetch_dataset(name="air_quality_valencia") # Data preparation # ============================================================================== air_quality = air_quality.interpolate(method="linear") air_quality = air_quality.sort_index() air_quality.head()

air_quality_valencia
--------------------
Hourly measures of several air quimical pollutant (pm2.5, co, no, no2, pm10,
nox, o3, so2) at Valencia city.
 Red de Vigilancia y Control de la Contaminación Atmosférica, 46250054-València
- Centre, https://mediambient.gva.es/es/web/calidad-ambiental/datos-historicos.
Shape of the dataset: (26304, 10)

Out[3]:

	pm2.5	co	no	no2	pm10	nox	o3	veloc.	direc.	so2
datetime
2019-01-01 00:00:00	19.0	0.2	3.0	36.0	22.0	40.0	16.0	0.5	262.0	8.0
2019-01-01 01:00:00	26.0	0.1	2.0	40.0	32.0	44.0	6.0	0.6	248.0	8.0
2019-01-01 02:00:00	31.0	0.1	11.0	42.0	36.0	58.0	3.0	0.3	224.0	8.0
2019-01-01 03:00:00	30.0	0.1	15.0	41.0	35.0	63.0	3.0	0.2	220.0	10.0
2019-01-01 04:00:00	30.0	0.1	16.0	39.0	36.0	63.0	3.0	0.4	221.0	11.0

In [5]:

# Checking the frequency of the time series
# ==============================================================================
print(f"Index: {air_quality.index.dtype}")
print(f"Frequency: {air_quality.index.freq}")

# Checking the frequency of the time series # ============================================================================== print(f"Index: {air_quality.index.dtype}") print(f"Frequency: {air_quality.index.freq}")

Index: datetime64[ns]
Frequency: <Hour>

In [6]:

# Split train-validation-test
# ==============================================================================
end_train = "2021-03-31 23:59:00"
end_validation = "2021-09-30 23:59:00"
air_quality_train = air_quality.loc[:end_train, :].copy()
air_quality_val = air_quality.loc[end_train:end_validation, :].copy()
air_quality_test = air_quality.loc[end_validation:, :].copy()

print(
    f"Dates train      : {air_quality_train.index.min()} --- " 
    f"{air_quality_train.index.max()}  (n={len(air_quality_train)})"
)
print(
    f"Dates validation : {air_quality_val.index.min()} --- " 
    f"{air_quality_val.index.max()}  (n={len(air_quality_val)})"
)
print(
    f"Dates test       : {air_quality_test.index.min()} --- " 
    f"{air_quality_test.index.max()}  (n={len(air_quality_test)})"
)

# Split train-validation-test # ============================================================================== end_train = "2021-03-31 23:59:00" end_validation = "2021-09-30 23:59:00" air_quality_train = air_quality.loc[:end_train, :].copy() air_quality_val = air_quality.loc[end_train:end_validation, :].copy() air_quality_test = air_quality.loc[end_validation:, :].copy() print( f"Dates train : {air_quality_train.index.min()} --- " f"{air_quality_train.index.max()} (n={len(air_quality_train)})" ) print( f"Dates validation : {air_quality_val.index.min()} --- " f"{air_quality_val.index.max()} (n={len(air_quality_val)})" ) print( f"Dates test : {air_quality_test.index.min()} --- " f"{air_quality_test.index.max()} (n={len(air_quality_test)})" )

Dates train      : 2019-01-01 00:00:00 --- 2021-03-31 23:00:00  (n=19704)
Dates validation : 2021-04-01 00:00:00 --- 2021-09-30 23:00:00  (n=4392)
Dates test       : 2021-10-01 00:00:00 --- 2021-12-31 23:00:00  (n=2208)

In [7]:

# Plotting one feature
# ==============================================================================
set_dark_theme()
fig, ax = plt.subplots(figsize=(8, 3))
air_quality_train["pm2.5"].rolling(100).mean().plot(ax=ax, label="train")
air_quality_val["pm2.5"].rolling(100).mean().plot(ax=ax, label="validation")
air_quality_test["pm2.5"].rolling(100).mean().plot(ax=ax, label="test")
ax.set_title("pm2.5")
ax.legend();

# Plotting one feature # ============================================================================== set_dark_theme() fig, ax = plt.subplots(figsize=(8, 3)) air_quality_train["pm2.5"].rolling(100).mean().plot(ax=ax, label="train") air_quality_val["pm2.5"].rolling(100).mean().plot(ax=ax, label="validation") air_quality_test["pm2.5"].rolling(100).mean().plot(ax=ax, label="test") ax.set_title("pm2.5") ax.legend();

Types of problems in time series modeling¶

1:1 Single-Step Forecasting - Predict one step ahead of a single series using the same series as predictor.¶

This type of problem involves modeling a time series using only its own past. It is a typical autoregressive problem.

Although tensorflow-keras facilitates the process of creating deep learning architectures, it is not always trivial to determine the Xtrain and Ytrain dimensions requiered to run an LSTM model. The dimensions depend on how many time series are being modeled, how many of them are are used as predictors, and the length of the prediction horizon.

✎ Note

The create_and_compile_model function is designed to facilitate the creation of the Tensorflow model. Advanced users can create their own architectures and pass them to the skforecast RNN Forecaster. Input and output dimensions must match the use case to which the model will be applied. the Annex at the end of the document for more details.

In [8]:

# Create model
# ==============================================================================
series = ["o3"] # Series used as predictors
levels = ["o3"] # Target serie to predict
lags = 32 # Past time steps to be used to predict the target
steps = 1 # Future time steps to be predicted

data = air_quality[series].copy()
data_train = air_quality_train[series].copy()
data_val = air_quality_val[series].copy()
data_test = air_quality_test[series].copy()

model = create_and_compile_model(
    series=data_train,
    levels=levels, 
    lags=lags,
    steps=steps,
    recurrent_layer="LSTM",
    recurrent_units=4,
    dense_units=16,
    optimizer=Adam(learning_rate=0.01), 
    loss=MeanSquaredError()
)
model.summary()

# Create model # ============================================================================== series = ["o3"] # Series used as predictors levels = ["o3"] # Target serie to predict lags = 32 # Past time steps to be used to predict the target steps = 1 # Future time steps to be predicted data = air_quality[series].copy() data_train = air_quality_train[series].copy() data_val = air_quality_val[series].copy() data_test = air_quality_test[series].copy() model = create_and_compile_model( series=data_train, levels=levels, lags=lags, steps=steps, recurrent_layer="LSTM", recurrent_units=4, dense_units=16, optimizer=Adam(learning_rate=0.01), loss=MeanSquaredError() ) model.summary()

Model: "model"
_________________________________________________________________
 Layer (type)                Output Shape              Param #   
=================================================================
 input_1 (InputLayer)        [(None, 32, 1)]           0         
                                                                 
 lstm (LSTM)                 (None, 4)                 96        
                                                                 
 dense (Dense)               (None, 16)                80        
                                                                 
 dense_1 (Dense)             (None, 1)                 17        
                                                                 
 reshape (Reshape)           (None, 1, 1)              0         
                                                                 
=================================================================
Total params: 193 (772.00 Byte)
Trainable params: 193 (772.00 Byte)
Non-trainable params: 0 (0.00 Byte)
_________________________________________________________________

In [9]:

# Forecaster Definition
# ==============================================================================
forecaster = ForecasterRnn(
    regressor=model,
    levels=levels,
    transformer_series=MinMaxScaler(),
    fit_kwargs={
        "epochs": 10,  # Number of epochs to train the model.
        "batch_size": 32,  # Batch size to train the model.
        "callbacks": [
            EarlyStopping(monitor="val_loss", patience=5)
        ],  # Callback to stop training when it is no longer learning.
        "series_val": data_val,  # Validation data for model training.
    },
)    

forecaster

# Forecaster Definition # ============================================================================== forecaster = ForecasterRnn( regressor=model, levels=levels, transformer_series=MinMaxScaler(), fit_kwargs={ "epochs": 10, # Number of epochs to train the model. "batch_size": 32, # Batch size to train the model. "callbacks": [ EarlyStopping(monitor="val_loss", patience=5) ], # Callback to stop training when it is no longer learning. "series_val": data_val, # Validation data for model training. }, ) forecaster

/home/ubuntu/anaconda3/envs/skforecast_12_py11/lib/python3.11/site-packages/skforecast/ForecasterRnn/ForecasterRnn.py:227: UserWarning: Setting `lags` = 'auto'. `lags` are inferred from the regressor architecture. Avoid the warning with lags=lags.
  warnings.warn(
/home/ubuntu/anaconda3/envs/skforecast_12_py11/lib/python3.11/site-packages/skforecast/ForecasterRnn/ForecasterRnn.py:257: UserWarning: `steps` default value = 'auto'. `steps` inferred from regressor architecture. Avoid the warning with steps=steps.
  warnings.warn(

Out[9]:

============= 
ForecasterRnn 
============= 
Regressor: <keras.src.engine.functional.Functional object at 0x7f49ab899650> 
Lags: [ 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
 25 26 27 28 29 30 31 32] 
Transformer for series: MinMaxScaler() 
Window size: 32 
Target series, levels: ['o3'] 
Multivariate series (names): None 
Maximum steps predicted: [1] 
Training range: None 
Training index type: None 
Training index frequency: None 
Model parameters: {'name': 'model', 'trainable': True, 'layers': [{'module': 'keras.layers', 'class_name': 'InputLayer', 'config': {'batch_input_shape': (None, 32, 1), 'dtype': 'float32', 'sparse': False, 'ragged': False, 'name': 'input_1'}, 'registered_name': None, 'name': 'input_1', 'inbound_nodes': []}, {'module': 'keras.layers', 'class_name': 'LSTM', 'config': {'name': 'lstm', 'trainable': True, 'dtype': 'float32', 'return_sequences': False, 'return_state': False, 'go_backwards': False, 'stateful': False, 'unroll': False, 'time_major': False, 'units': 4, 'activation': 'relu', 'recurrent_activation': 'sigmoid', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'recurrent_initializer': {'module': 'keras.initializers', 'class_name': 'Orthogonal', 'config': {'gain': 1.0, 'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'unit_forget_bias': True, 'kernel_regularizer': None, 'recurrent_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'recurrent_constraint': None, 'bias_constraint': None, 'dropout': 0.0, 'recurrent_dropout': 0.0, 'implementation': 2}, 'registered_name': None, 'build_config': {'input_shape': (None, 32, 1)}, 'name': 'lstm', 'inbound_nodes': [[['input_1', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense', 'trainable': True, 'dtype': 'float32', 'units': 16, 'activation': 'relu', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 4)}, 'name': 'dense', 'inbound_nodes': [[['lstm', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_1', 'trainable': True, 'dtype': 'float32', 'units': 1, 'activation': 'linear', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 16)}, 'name': 'dense_1', 'inbound_nodes': [[['dense', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Reshape', 'config': {'name': 'reshape', 'trainable': True, 'dtype': 'float32', 'target_shape': (1, 1)}, 'registered_name': None, 'build_config': {'input_shape': (None, 1)}, 'name': 'reshape', 'inbound_nodes': [[['dense_1', 0, 0, {}]]]}], 'input_layers': [['input_1', 0, 0]], 'output_layers': [['reshape', 0, 0]]} 
Compile parameters: {'optimizer': {'module': 'keras.optimizers', 'class_name': 'Adam', 'config': {'name': 'Adam', 'weight_decay': None, 'clipnorm': None, 'global_clipnorm': None, 'clipvalue': None, 'use_ema': False, 'ema_momentum': 0.99, 'ema_overwrite_frequency': None, 'jit_compile': False, 'is_legacy_optimizer': False, 'learning_rate': 0.009999999776482582, 'beta_1': 0.9, 'beta_2': 0.999, 'epsilon': 1e-07, 'amsgrad': False}, 'registered_name': None}, 'loss': {'module': 'keras.losses', 'class_name': 'MeanSquaredError', 'config': {'reduction': 'auto', 'name': 'mean_squared_error', 'fn': 'mean_squared_error'}, 'registered_name': None}, 'metrics': None, 'loss_weights': None, 'weighted_metrics': None, 'run_eagerly': None, 'steps_per_execution': None, 'jit_compile': None} 
fit_kwargs: {'epochs': 10, 'batch_size': 32, 'callbacks': [<keras.src.callbacks.EarlyStopping object at 0x7f49abbefcd0>]} 
Creation date: 2024-05-05 13:07:44 
Last fit date: None 
Skforecast version: 0.12.0 
Python version: 3.11.8 
Forecaster id: None 

⚠ Warning

The output warning indicates that the number of lags has been inferred from the model architecture. In this case, the model has an LSTM layer with 32 neurons, so the number of lags is 32. If a different number of lags is desired, the lags argument can be specified in the create_and_compile_model function. To omit the warning, set lags=lags and steps=steps arguments can be specified in the initialization of the ForecasterRnn.

In [10]:

# Fit forecaster
# ==============================================================================
forecaster.fit(data_train)

# Fit forecaster # ============================================================================== forecaster.fit(data_train)

Epoch 1/10
615/615 [==============================] - 8s 11ms/step - loss: 0.0103 - val_loss: 0.0065
Epoch 2/10
615/615 [==============================] - 6s 10ms/step - loss: 0.0057 - val_loss: 0.0061
Epoch 3/10
615/615 [==============================] - 6s 10ms/step - loss: 0.0056 - val_loss: 0.0058
Epoch 4/10
615/615 [==============================] - 6s 10ms/step - loss: 0.0055 - val_loss: 0.0057
Epoch 5/10
615/615 [==============================] - 6s 10ms/step - loss: 0.0056 - val_loss: 0.0058
Epoch 6/10
615/615 [==============================] - 6s 10ms/step - loss: 0.0055 - val_loss: 0.0057
Epoch 7/10
615/615 [==============================] - 6s 10ms/step - loss: 0.0055 - val_loss: 0.0067
Epoch 8/10
615/615 [==============================] - 6s 10ms/step - loss: 0.0054 - val_loss: 0.0057
Epoch 9/10
615/615 [==============================] - 6s 10ms/step - loss: 0.0055 - val_loss: 0.0057
Epoch 10/10
615/615 [==============================] - 6s 10ms/step - loss: 0.0054 - val_loss: 0.0061

Overfitting can be tracked by moniting the loss function on the validation set. Metrics are automatically stored in the history attribute of the ForecasterRnn object. The method plot_history can be used to visualize the training and validation loss.

In [11]:

# Track training and overfitting
# ==============================================================================
fig, ax = plt.subplots(figsize=(6, 2.5))
forecaster.plot_history(ax=ax)

# Track training and overfitting # ============================================================================== fig, ax = plt.subplots(figsize=(6, 2.5)) forecaster.plot_history(ax=ax)

In [12]:

# Predictions
# ==============================================================================
predictions = forecaster.predict()
predictions

# Predictions # ============================================================================== predictions = forecaster.predict() predictions

Out[12]:

	o3
2021-04-01	46.41996

In [13]:

# Backtesting with test data
# ==============================================================================
metrics, predictions = backtesting_forecaster_multiseries(
    forecaster=forecaster,
    steps=forecaster.max_step,
    series=data,
    levels=forecaster.levels,
    initial_train_size=len(data.loc[:end_validation, :]), # Training + Validation Data
    metric="mean_absolute_error",
    verbose=False, # Set to True to print detailed information
    refit=False,
)

# Backtesting with test data # ============================================================================== metrics, predictions = backtesting_forecaster_multiseries( forecaster=forecaster, steps=forecaster.max_step, series=data, levels=forecaster.levels, initial_train_size=len(data.loc[:end_validation, :]), # Training + Validation Data metric="mean_absolute_error", verbose=False, # Set to True to print detailed information refit=False, )

Epoch 1/10
752/752 [==============================] - 7s 8ms/step - loss: 0.0054 - val_loss: 0.0055
Epoch 2/10
752/752 [==============================] - 6s 8ms/step - loss: 0.0054 - val_loss: 0.0057
Epoch 3/10
752/752 [==============================] - 6s 8ms/step - loss: 0.0054 - val_loss: 0.0065
Epoch 4/10
752/752 [==============================] - 6s 8ms/step - loss: 0.0054 - val_loss: 0.0056
Epoch 5/10
752/752 [==============================] - 6s 8ms/step - loss: 0.0054 - val_loss: 0.0055
Epoch 6/10
752/752 [==============================] - 6s 8ms/step - loss: 0.0055 - val_loss: 0.0055
Epoch 7/10
752/752 [==============================] - 6s 8ms/step - loss: 0.0054 - val_loss: 0.0058
Epoch 8/10
752/752 [==============================] - 6s 8ms/step - loss: 0.0054 - val_loss: 0.0066
Epoch 9/10
752/752 [==============================] - 6s 8ms/step - loss: 0.0054 - val_loss: 0.0056
Epoch 10/10
752/752 [==============================] - 6s 8ms/step - loss: 0.0054 - val_loss: 0.0056

  0%|          | 0/2208 [00:00<?, ?it/s]

In [14]:

# Backtesting predictions
# ==============================================================================
predictions

# Backtesting predictions # ============================================================================== predictions

Out[14]:

	o3
2021-10-01 00:00:00	57.153248
2021-10-01 01:00:00	61.629093
2021-10-01 02:00:00	65.515518
2021-10-01 03:00:00	65.715500
2021-10-01 04:00:00	56.098572
...	...
2021-12-31 19:00:00	19.313316
2021-12-31 20:00:00	19.015085
2021-12-31 21:00:00	19.415157
2021-12-31 22:00:00	19.234400
2021-12-31 23:00:00	20.594242

2208 rows × 1 columns

In [15]:

# % Error vs series mean
# ==============================================================================
rel_mse = 100 * metrics.loc[0, 'mean_absolute_error'] / np.mean(data["o3"])
print(f"Serie mean: {np.mean(data['o3']):0.2f}")
print(f"Relative error (mae): {rel_mse:0.2f} %")

# % Error vs series mean # ============================================================================== rel_mse = 100 * metrics.loc[0, 'mean_absolute_error'] / np.mean(data["o3"]) print(f"Serie mean: {np.mean(data['o3']):0.2f}") print(f"Relative error (mae): {rel_mse:0.2f} %")

Serie mean: 54.52
Relative error (mae): 11.91 %

In [16]:

# Plotting predictions vs real values in the test set
# ==============================================================================
fig, ax = plt.subplots(figsize=(8, 3))
data_test["o3"].plot(ax=ax, label="test")
predictions["o3"].plot(ax=ax, label="predictions")
ax.set_title("O3")
ax.legend();

# Plotting predictions vs real values in the test set # ============================================================================== fig, ax = plt.subplots(figsize=(8, 3)) data_test["o3"].plot(ax=ax, label="test") predictions["o3"].plot(ax=ax, label="predictions") ax.set_title("O3") ax.legend();

1:1 Multiple-Step Forecasting - Predict a single series using the same series as predictor. Multiple steps ahead.¶

The next case is similar to the previous one, but now the goal is to predict multiple future values. In this scenario multiple future steps of a single time series are modeled using only its past values.

A similar architecture to the previous one will be used, but with a greater number of neurons in the LSTM layer and in the first dense layer. This will allow the model to have greater flexibility to predict the time series.

In [17]:

# Model creation
# ==============================================================================
series = ["o3"] # Series used as predictors
levels = ["o3"] # Target serie to predict
lags = 32 # Past time steps to be used to predict the target
steps = 5 # Future time steps to be predicted

model = create_and_compile_model(
    series=data_train,
    levels=levels, 
    lags=lags,
    steps=steps,
    recurrent_layer="LSTM",
    recurrent_units=50,
    dense_units=32,
    optimizer=Adam(learning_rate=0.01), 
    loss=MeanSquaredError()
)
model.summary()

# Model creation # ============================================================================== series = ["o3"] # Series used as predictors levels = ["o3"] # Target serie to predict lags = 32 # Past time steps to be used to predict the target steps = 5 # Future time steps to be predicted model = create_and_compile_model( series=data_train, levels=levels, lags=lags, steps=steps, recurrent_layer="LSTM", recurrent_units=50, dense_units=32, optimizer=Adam(learning_rate=0.01), loss=MeanSquaredError() ) model.summary()

Model: "model_1"
_________________________________________________________________
 Layer (type)                Output Shape              Param #   
=================================================================
 input_2 (InputLayer)        [(None, 32, 1)]           0         
                                                                 
 lstm_1 (LSTM)               (None, 50)                10400     
                                                                 
 dense_2 (Dense)             (None, 32)                1632      
                                                                 
 dense_3 (Dense)             (None, 5)                 165       
                                                                 
 reshape_1 (Reshape)         (None, 5, 1)              0         
                                                                 
=================================================================
Total params: 12197 (47.64 KB)
Trainable params: 12197 (47.64 KB)
Non-trainable params: 0 (0.00 Byte)
_________________________________________________________________

In [18]:

# Forecaster Creation
# ==============================================================================
forecaster = ForecasterRnn(
    regressor=model,
    levels=levels,
    transformer_series=MinMaxScaler(),
    fit_kwargs={
        "epochs": 3,  # Number of epochs to train the model.
        "batch_size": 32,  # Batch size to train the model.
        "callbacks": [
            EarlyStopping(monitor="val_loss", patience=5)
        ],  # Callback to stop training when it is no longer learning.
        "series_val": data_val,  # Validation data for model training.
    },
)    

forecaster

# Forecaster Creation # ============================================================================== forecaster = ForecasterRnn( regressor=model, levels=levels, transformer_series=MinMaxScaler(), fit_kwargs={ "epochs": 3, # Number of epochs to train the model. "batch_size": 32, # Batch size to train the model. "callbacks": [ EarlyStopping(monitor="val_loss", patience=5) ], # Callback to stop training when it is no longer learning. "series_val": data_val, # Validation data for model training. }, ) forecaster

/home/ubuntu/anaconda3/envs/skforecast_12_py11/lib/python3.11/site-packages/skforecast/ForecasterRnn/ForecasterRnn.py:227: UserWarning: Setting `lags` = 'auto'. `lags` are inferred from the regressor architecture. Avoid the warning with lags=lags.
  warnings.warn(
/home/ubuntu/anaconda3/envs/skforecast_12_py11/lib/python3.11/site-packages/skforecast/ForecasterRnn/ForecasterRnn.py:257: UserWarning: `steps` default value = 'auto'. `steps` inferred from regressor architecture. Avoid the warning with steps=steps.
  warnings.warn(

Out[18]:

============= 
ForecasterRnn 
============= 
Regressor: <keras.src.engine.functional.Functional object at 0x7f49a2746c10> 
Lags: [ 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
 25 26 27 28 29 30 31 32] 
Transformer for series: MinMaxScaler() 
Window size: 32 
Target series, levels: ['o3'] 
Multivariate series (names): None 
Maximum steps predicted: [1 2 3 4 5] 
Training range: None 
Training index type: None 
Training index frequency: None 
Model parameters: {'name': 'model_1', 'trainable': True, 'layers': [{'module': 'keras.layers', 'class_name': 'InputLayer', 'config': {'batch_input_shape': (None, 32, 1), 'dtype': 'float32', 'sparse': False, 'ragged': False, 'name': 'input_2'}, 'registered_name': None, 'name': 'input_2', 'inbound_nodes': []}, {'module': 'keras.layers', 'class_name': 'LSTM', 'config': {'name': 'lstm_1', 'trainable': True, 'dtype': 'float32', 'return_sequences': False, 'return_state': False, 'go_backwards': False, 'stateful': False, 'unroll': False, 'time_major': False, 'units': 50, 'activation': 'relu', 'recurrent_activation': 'sigmoid', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'recurrent_initializer': {'module': 'keras.initializers', 'class_name': 'Orthogonal', 'config': {'gain': 1.0, 'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'unit_forget_bias': True, 'kernel_regularizer': None, 'recurrent_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'recurrent_constraint': None, 'bias_constraint': None, 'dropout': 0.0, 'recurrent_dropout': 0.0, 'implementation': 2}, 'registered_name': None, 'build_config': {'input_shape': (None, 32, 1)}, 'name': 'lstm_1', 'inbound_nodes': [[['input_2', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_2', 'trainable': True, 'dtype': 'float32', 'units': 32, 'activation': 'relu', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 50)}, 'name': 'dense_2', 'inbound_nodes': [[['lstm_1', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_3', 'trainable': True, 'dtype': 'float32', 'units': 5, 'activation': 'linear', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 32)}, 'name': 'dense_3', 'inbound_nodes': [[['dense_2', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Reshape', 'config': {'name': 'reshape_1', 'trainable': True, 'dtype': 'float32', 'target_shape': (5, 1)}, 'registered_name': None, 'build_config': {'input_shape': (None, 5)}, 'name': 'reshape_1', 'inbound_nodes': [[['dense_3', 0, 0, {}]]]}], 'input_layers': [['input_2', 0, 0]], 'output_layers': [['reshape_1', 0, 0]]} 
Compile parameters: {'optimizer': {'module': 'keras.optimizers', 'class_name': 'Adam', 'config': {'name': 'Adam', 'weight_decay': None, 'clipnorm': None, 'global_clipnorm': None, 'clipvalue': None, 'use_ema': False, 'ema_momentum': 0.99, 'ema_overwrite_frequency': None, 'jit_compile': False, 'is_legacy_optimizer': False, 'learning_rate': 0.009999999776482582, 'beta_1': 0.9, 'beta_2': 0.999, 'epsilon': 1e-07, 'amsgrad': False}, 'registered_name': None}, 'loss': {'module': 'keras.losses', 'class_name': 'MeanSquaredError', 'config': {'reduction': 'auto', 'name': 'mean_squared_error', 'fn': 'mean_squared_error'}, 'registered_name': None}, 'metrics': None, 'loss_weights': None, 'weighted_metrics': None, 'run_eagerly': None, 'steps_per_execution': None, 'jit_compile': None} 
fit_kwargs: {'epochs': 3, 'batch_size': 32, 'callbacks': [<keras.src.callbacks.EarlyStopping object at 0x7f49a280abd0>]} 
Creation date: 2024-05-05 13:12:44 
Last fit date: None 
Skforecast version: 0.12.0 
Python version: 3.11.8 
Forecaster id: None 

✎ Note

The fit_kwargs parameter allows the user to set any Tensorflow-based configuration in the model. In the example, 10 training epochs are defined with a batch size of 32. An EarlyStopping callback is configured to stop training when the validation loss stops decreasing for 5 epochs (patience=5). Other callbacks can also be configured, such as ModelCheckpoint to save the model at each epoch, or even Tensorboard to visualize the training and validation loss in real time.

In [19]:

# Fit forecaster
# ==============================================================================
forecaster.fit(data_train)

# Fit forecaster # ============================================================================== forecaster.fit(data_train)

Epoch 1/3
615/615 [==============================] - 11s 15ms/step - loss: 0.0439 - val_loss: 0.0282
Epoch 2/3
615/615 [==============================] - 9s 15ms/step - loss: 0.0242 - val_loss: 0.0238
Epoch 3/3
615/615 [==============================] - 9s 14ms/step - loss: 0.0226 - val_loss: 0.0208

In [20]:

# Train and overfitting tracking
# ==============================================================================
fig, ax = plt.subplots(figsize=(6, 2.5))
forecaster.plot_history(ax=ax)

# Train and overfitting tracking # ============================================================================== fig, ax = plt.subplots(figsize=(6, 2.5)) forecaster.plot_history(ax=ax)

In [21]:

# Prediction
# ==============================================================================
predictions = forecaster.predict()
predictions

# Prediction # ============================================================================== predictions = forecaster.predict() predictions

Out[21]:

	o3
2021-04-01 00:00:00	58.094482
2021-04-01 01:00:00	54.829151
2021-04-01 02:00:00	56.895340
2021-04-01 03:00:00	55.185181
2021-04-01 04:00:00	55.783127

In [22]:

# Specific step predictions
# ==============================================================================
predictions = forecaster.predict(steps=[1, 3])
predictions

# Specific step predictions # ============================================================================== predictions = forecaster.predict(steps=[1, 3]) predictions

Out[22]:

	o3
2021-04-01 00:00:00	58.094482
2021-04-01 02:00:00	56.895340

In [23]:

# Backtesting 
# ==============================================================================
metrics, predictions = backtesting_forecaster_multiseries(
    forecaster=forecaster,
    steps=forecaster.max_step,
    series=data,
    levels=forecaster.levels,
    initial_train_size=len(data.loc[:end_validation, :]),
    metric="mean_absolute_error",
    verbose=False,
    refit=False,
)

# Backtesting # ============================================================================== metrics, predictions = backtesting_forecaster_multiseries( forecaster=forecaster, steps=forecaster.max_step, series=data, levels=forecaster.levels, initial_train_size=len(data.loc[:end_validation, :]), metric="mean_absolute_error", verbose=False, refit=False, )

Epoch 1/3
752/752 [==============================] - 12s 14ms/step - loss: 0.0213 - val_loss: 0.0197
Epoch 2/3
752/752 [==============================] - 10s 14ms/step - loss: 0.0204 - val_loss: 0.0176
Epoch 3/3
752/752 [==============================] - 11s 14ms/step - loss: 0.0188 - val_loss: 0.0180

  0%|          | 0/442 [00:00<?, ?it/s]

In [24]:

# Backtesting predictions
# ==============================================================================
predictions

# Backtesting predictions # ============================================================================== predictions

Out[24]:

	o3
2021-10-01 00:00:00	57.464813
2021-10-01 01:00:00	56.058838
2021-10-01 02:00:00	56.489147
2021-10-01 03:00:00	56.938538
2021-10-01 04:00:00	54.937553
...	...
2021-12-31 19:00:00	49.658962
2021-12-31 20:00:00	48.403797
2021-12-31 21:00:00	15.085720
2021-12-31 22:00:00	19.390947
2021-12-31 23:00:00	23.478308

2208 rows × 1 columns

In [25]:

# Plotting predictions vs real values in the test set
# ==============================================================================
fig, ax = plt.subplots(figsize=(8, 3))
data_test["o3"].plot(ax=ax, label="test")
predictions["o3"].plot(ax=ax, label="predictions")
ax.set_title("O3")
ax.legend();

# Plotting predictions vs real values in the test set # ============================================================================== fig, ax = plt.subplots(figsize=(8, 3)) data_test["o3"].plot(ax=ax, label="test") predictions["o3"].plot(ax=ax, label="predictions") ax.set_title("O3") ax.legend();

In [26]:

# Backtesting metrics
# ==============================================================================
metrics

# Backtesting metrics # ============================================================================== metrics

Out[26]:

	levels	mean_absolute_error
0	o3	13.359329

In [27]:

# % Error vs series mean
# ==============================================================================
rel_mse = 100 * metrics.loc[0, 'mean_absolute_error'] / np.mean(data["o3"])
print(f"Serie mean: {np.mean(data['o3']):0.2f}")
print(f"Relative error (mae): {rel_mse:0.2f} %")

# % Error vs series mean # ============================================================================== rel_mse = 100 * metrics.loc[0, 'mean_absolute_error'] / np.mean(data["o3"]) print(f"Serie mean: {np.mean(data['o3']):0.2f}") print(f"Relative error (mae): {rel_mse:0.2f} %")

Serie mean: 54.52
Relative error (mae): 24.50 %

N:1 Multiple-Step Forecasting - Predict one series using multiple series as predictors.¶

In this case, a single series will be predicted, but using multiple time series as predictors. Now, the past values of multiple time series will influence the prediction of a single time series.

In [28]:

# Model creation
# ==============================================================================
# Time series used in the training. Now, it is multiseries
series = ['pm2.5', 'co', 'no', 'no2', 'pm10', 'nox', 'o3', 'veloc.', 'direc.','so2'] 
levels = ["o3"] 
lags = 32 
steps = 5 

data = air_quality[series].copy()
data_train = air_quality_train[series].copy()
data_val = air_quality_val[series].copy()
data_test = air_quality_test[series].copy()

model = create_and_compile_model(
    series=data_train,
    levels=levels, 
    lags=lags,
    steps=steps,
    recurrent_layer="LSTM",
    recurrent_units=[100, 50],
    dense_units=[64, 32],
    optimizer=Adam(learning_rate=0.01), 
    loss=MeanSquaredError()
)
model.summary()

# Model creation # ============================================================================== # Time series used in the training. Now, it is multiseries series = ['pm2.5', 'co', 'no', 'no2', 'pm10', 'nox', 'o3', 'veloc.', 'direc.','so2'] levels = ["o3"] lags = 32 steps = 5 data = air_quality[series].copy() data_train = air_quality_train[series].copy() data_val = air_quality_val[series].copy() data_test = air_quality_test[series].copy() model = create_and_compile_model( series=data_train, levels=levels, lags=lags, steps=steps, recurrent_layer="LSTM", recurrent_units=[100, 50], dense_units=[64, 32], optimizer=Adam(learning_rate=0.01), loss=MeanSquaredError() ) model.summary()

Model: "model_2"
_________________________________________________________________
 Layer (type)                Output Shape              Param #   
=================================================================
 input_3 (InputLayer)        [(None, 32, 10)]          0         
                                                                 
 lstm_2 (LSTM)               (None, 32, 100)           44400     
                                                                 
 lstm_3 (LSTM)               (None, 50)                30200     
                                                                 
 dense_4 (Dense)             (None, 64)                3264      
                                                                 
 dense_5 (Dense)             (None, 32)                2080      
                                                                 
 dense_6 (Dense)             (None, 5)                 165       
                                                                 
 reshape_2 (Reshape)         (None, 5, 1)              0         
                                                                 
=================================================================
Total params: 80109 (312.93 KB)
Trainable params: 80109 (312.93 KB)
Non-trainable params: 0 (0.00 Byte)
_________________________________________________________________

In [29]:

# Forecaster creation
# ==============================================================================
forecaster = ForecasterRnn(
    regressor=model,
    levels=levels,
    steps=steps,
    lags=lags,
    transformer_series=MinMaxScaler(),
    fit_kwargs={
        "epochs": 4,  
        "batch_size": 128,  
        "series_val": data_val,
    },
)
forecaster

# Forecaster creation # ============================================================================== forecaster = ForecasterRnn( regressor=model, levels=levels, steps=steps, lags=lags, transformer_series=MinMaxScaler(), fit_kwargs={ "epochs": 4, "batch_size": 128, "series_val": data_val, }, ) forecaster

Out[29]:

============= 
ForecasterRnn 
============= 
Regressor: <keras.src.engine.functional.Functional object at 0x7f49a299bdd0> 
Lags: [ 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
 25 26 27 28 29 30 31 32] 
Transformer for series: MinMaxScaler() 
Window size: 32 
Target series, levels: ['o3'] 
Multivariate series (names): None 
Maximum steps predicted: [1 2 3 4 5] 
Training range: None 
Training index type: None 
Training index frequency: None 
Model parameters: {'name': 'model_2', 'trainable': True, 'layers': [{'module': 'keras.layers', 'class_name': 'InputLayer', 'config': {'batch_input_shape': (None, 32, 10), 'dtype': 'float32', 'sparse': False, 'ragged': False, 'name': 'input_3'}, 'registered_name': None, 'name': 'input_3', 'inbound_nodes': []}, {'module': 'keras.layers', 'class_name': 'LSTM', 'config': {'name': 'lstm_2', 'trainable': True, 'dtype': 'float32', 'return_sequences': True, 'return_state': False, 'go_backwards': False, 'stateful': False, 'unroll': False, 'time_major': False, 'units': 100, 'activation': 'relu', 'recurrent_activation': 'sigmoid', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'recurrent_initializer': {'module': 'keras.initializers', 'class_name': 'Orthogonal', 'config': {'gain': 1.0, 'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'unit_forget_bias': True, 'kernel_regularizer': None, 'recurrent_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'recurrent_constraint': None, 'bias_constraint': None, 'dropout': 0.0, 'recurrent_dropout': 0.0, 'implementation': 2}, 'registered_name': None, 'build_config': {'input_shape': (None, 32, 10)}, 'name': 'lstm_2', 'inbound_nodes': [[['input_3', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'LSTM', 'config': {'name': 'lstm_3', 'trainable': True, 'dtype': 'float32', 'return_sequences': False, 'return_state': False, 'go_backwards': False, 'stateful': False, 'unroll': False, 'time_major': False, 'units': 50, 'activation': 'relu', 'recurrent_activation': 'sigmoid', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'recurrent_initializer': {'module': 'keras.initializers', 'class_name': 'Orthogonal', 'config': {'gain': 1.0, 'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'unit_forget_bias': True, 'kernel_regularizer': None, 'recurrent_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'recurrent_constraint': None, 'bias_constraint': None, 'dropout': 0.0, 'recurrent_dropout': 0.0, 'implementation': 2}, 'registered_name': None, 'build_config': {'input_shape': (None, 32, 100)}, 'name': 'lstm_3', 'inbound_nodes': [[['lstm_2', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_4', 'trainable': True, 'dtype': 'float32', 'units': 64, 'activation': 'relu', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 50)}, 'name': 'dense_4', 'inbound_nodes': [[['lstm_3', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_5', 'trainable': True, 'dtype': 'float32', 'units': 32, 'activation': 'relu', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 64)}, 'name': 'dense_5', 'inbound_nodes': [[['dense_4', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_6', 'trainable': True, 'dtype': 'float32', 'units': 5, 'activation': 'linear', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 32)}, 'name': 'dense_6', 'inbound_nodes': [[['dense_5', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Reshape', 'config': {'name': 'reshape_2', 'trainable': True, 'dtype': 'float32', 'target_shape': (5, 1)}, 'registered_name': None, 'build_config': {'input_shape': (None, 5)}, 'name': 'reshape_2', 'inbound_nodes': [[['dense_6', 0, 0, {}]]]}], 'input_layers': [['input_3', 0, 0]], 'output_layers': [['reshape_2', 0, 0]]} 
Compile parameters: {'optimizer': {'module': 'keras.optimizers', 'class_name': 'Adam', 'config': {'name': 'Adam', 'weight_decay': None, 'clipnorm': None, 'global_clipnorm': None, 'clipvalue': None, 'use_ema': False, 'ema_momentum': 0.99, 'ema_overwrite_frequency': None, 'jit_compile': False, 'is_legacy_optimizer': False, 'learning_rate': 0.009999999776482582, 'beta_1': 0.9, 'beta_2': 0.999, 'epsilon': 1e-07, 'amsgrad': False}, 'registered_name': None}, 'loss': {'module': 'keras.losses', 'class_name': 'MeanSquaredError', 'config': {'reduction': 'auto', 'name': 'mean_squared_error', 'fn': 'mean_squared_error'}, 'registered_name': None}, 'metrics': None, 'loss_weights': None, 'weighted_metrics': None, 'run_eagerly': None, 'steps_per_execution': None, 'jit_compile': None} 
fit_kwargs: {'epochs': 4, 'batch_size': 128} 
Creation date: 2024-05-05 13:14:23 
Last fit date: None 
Skforecast version: 0.12.0 
Python version: 3.11.8 
Forecaster id: None 

In [30]:

# Fit forecaster
# ==============================================================================
forecaster.fit(data_train)

# Fit forecaster # ============================================================================== forecaster.fit(data_train)

Epoch 1/4
154/154 [==============================] - 16s 85ms/step - loss: 0.0656 - val_loss: 0.0389
Epoch 2/4
154/154 [==============================] - 13s 83ms/step - loss: 0.0207 - val_loss: 0.0151
Epoch 3/4
154/154 [==============================] - 13s 83ms/step - loss: 0.0120 - val_loss: 0.0147
Epoch 4/4
154/154 [==============================] - 13s 83ms/step - loss: 0.0106 - val_loss: 0.0118

In [31]:

# Trainig and overfitting tracking
# ==============================================================================
fig, ax = plt.subplots(figsize=(7, 3))
forecaster.plot_history(ax=ax)

# Trainig and overfitting tracking # ============================================================================== fig, ax = plt.subplots(figsize=(7, 3)) forecaster.plot_history(ax=ax)

In [32]:

# Prediction
# ==============================================================================
predictions = forecaster.predict()
predictions

# Prediction # ============================================================================== predictions = forecaster.predict() predictions

Out[32]:

	o3
2021-04-01 00:00:00	44.399467
2021-04-01 01:00:00	41.982407
2021-04-01 02:00:00	36.779495
2021-04-01 03:00:00	32.011993
2021-04-01 04:00:00	28.510212

In [33]:

# Backtesting with test data
# ==============================================================================
metrics, predictions = backtesting_forecaster_multiseries(
    forecaster=forecaster,
    steps=forecaster.max_step,
    series=data,
    levels=forecaster.levels,
    initial_train_size=len(data.loc[:end_validation, :]), # Datos de entrenamiento + validación
    metric="mean_absolute_error",
    verbose=False,
    refit=False,
)

# Backtesting with test data # ============================================================================== metrics, predictions = backtesting_forecaster_multiseries( forecaster=forecaster, steps=forecaster.max_step, series=data, levels=forecaster.levels, initial_train_size=len(data.loc[:end_validation, :]), # Datos de entrenamiento + validación metric="mean_absolute_error", verbose=False, refit=False, )

Epoch 1/4
188/188 [==============================] - 18s 85ms/step - loss: 0.0103 - val_loss: 0.0111
Epoch 2/4
188/188 [==============================] - 15s 82ms/step - loss: 0.0100 - val_loss: 0.0106
Epoch 3/4
188/188 [==============================] - 15s 81ms/step - loss: 0.0099 - val_loss: 0.0116
Epoch 4/4
188/188 [==============================] - 15s 81ms/step - loss: 0.0097 - val_loss: 0.0113

  0%|          | 0/442 [00:00<?, ?it/s]

In [34]:

# Backtesting metrics
# ==============================================================================
metrics

# Backtesting metrics # ============================================================================== metrics

Out[34]:

	levels	mean_absolute_error
0	o3	10.476242

In [35]:

# % Error vs series mean
# ==============================================================================
rel_mse = 100 * metrics.loc[0, 'mean_absolute_error'] / np.mean(data["o3"])
print(f"Serie mean: {np.mean(data['o3']):0.2f}")
print(f"Relative error (mae): {rel_mse:0.2f} %")

# % Error vs series mean # ============================================================================== rel_mse = 100 * metrics.loc[0, 'mean_absolute_error'] / np.mean(data["o3"]) print(f"Serie mean: {np.mean(data['o3']):0.2f}") print(f"Relative error (mae): {rel_mse:0.2f} %")

Serie mean: 54.52
Relative error (mae): 19.22 %

In [36]:

# Backtesting predictions
# ==============================================================================
predictions

# Backtesting predictions # ============================================================================== predictions

Out[36]:

	o3
2021-10-01 00:00:00	45.452110
2021-10-01 01:00:00	44.329891
2021-10-01 02:00:00	39.511284
2021-10-01 03:00:00	34.766834
2021-10-01 04:00:00	31.255672
...	...
2021-12-31 19:00:00	11.621369
2021-12-31 20:00:00	7.082984
2021-12-31 21:00:00	4.187407
2021-12-31 22:00:00	7.278923
2021-12-31 23:00:00	8.782186

2208 rows × 1 columns

In [37]:

# Plotting predictions vs real values in the test set
# ==============================================================================
fig, ax = plt.subplots(figsize=(8, 3))
data_test["o3"].plot(ax=ax, label="test")
predictions["o3"].plot(ax=ax, label="predictions")
ax.set_title("O3")
ax.legend();

# Plotting predictions vs real values in the test set # ============================================================================== fig, ax = plt.subplots(figsize=(8, 3)) data_test["o3"].plot(ax=ax, label="test") predictions["o3"].plot(ax=ax, label="predictions") ax.set_title("O3") ax.legend();

N:M Multiple-Step Forecasting - Multiple time series with multiple outputs¶

This is a more complex scenario in which multiple time series are predicted using multiple time series as predictors. It is therefore a scenario in which multiple series are modeled simultaneously using a single model. This has special application in many real scenarios, such as the prediction of stock values for several companies based on the stock history, the price of energy and commodities. Or the case of forecasting multiple products in an online store, based on the sales of other products, the price of the products, etc.

In [38]:

# Model creation
# ==============================================================================
# Now, we have multiple series and multiple targets
series = ['pm2.5', 'co', 'no', 'no2', 'pm10', 'nox', 'o3', 'veloc.', 'direc.','so2'] 
levels = ['pm2.5', 'co', 'no', "o3"] #  Features to predict. It can be all the series or less
lags = 32 
steps = 5 

data = air_quality[series].copy()
data_train = air_quality_train[series].copy()
data_val = air_quality_val[series].copy()
data_test = air_quality_test[series].copy()

model = create_and_compile_model(
    series=data_train,
    levels=levels, 
    lags=lags,
    steps=steps,
    recurrent_layer="LSTM",
    recurrent_units=[100, 50],
    dense_units=[64, 32],
    optimizer=Adam(learning_rate=0.01), 
    loss=MeanSquaredError()
)
model.summary()

# Model creation # ============================================================================== # Now, we have multiple series and multiple targets series = ['pm2.5', 'co', 'no', 'no2', 'pm10', 'nox', 'o3', 'veloc.', 'direc.','so2'] levels = ['pm2.5', 'co', 'no', "o3"] # Features to predict. It can be all the series or less lags = 32 steps = 5 data = air_quality[series].copy() data_train = air_quality_train[series].copy() data_val = air_quality_val[series].copy() data_test = air_quality_test[series].copy() model = create_and_compile_model( series=data_train, levels=levels, lags=lags, steps=steps, recurrent_layer="LSTM", recurrent_units=[100, 50], dense_units=[64, 32], optimizer=Adam(learning_rate=0.01), loss=MeanSquaredError() ) model.summary()

Model: "model_3"
_________________________________________________________________
 Layer (type)                Output Shape              Param #   
=================================================================
 input_4 (InputLayer)        [(None, 32, 10)]          0         
                                                                 
 lstm_4 (LSTM)               (None, 32, 100)           44400     
                                                                 
 lstm_5 (LSTM)               (None, 50)                30200     
                                                                 
 dense_7 (Dense)             (None, 64)                3264      
                                                                 
 dense_8 (Dense)             (None, 32)                2080      
                                                                 
 dense_9 (Dense)             (None, 20)                660       
                                                                 
 reshape_3 (Reshape)         (None, 5, 4)              0         
                                                                 
=================================================================
Total params: 80604 (314.86 KB)
Trainable params: 80604 (314.86 KB)
Non-trainable params: 0 (0.00 Byte)
_________________________________________________________________

In [39]:

# Forecaster creation
# ==============================================================================
forecaster = ForecasterRnn(
    regressor=model,
    levels=levels,
    steps=steps,
    lags=lags,
    transformer_series=MinMaxScaler(),
    fit_kwargs={
        "epochs": 10, 
        "batch_size": 128, 
        "callbacks": [
            EarlyStopping(monitor="val_loss", patience=3)
        ],  
        "series_val": data_val,
    },
)
forecaster

# Forecaster creation # ============================================================================== forecaster = ForecasterRnn( regressor=model, levels=levels, steps=steps, lags=lags, transformer_series=MinMaxScaler(), fit_kwargs={ "epochs": 10, "batch_size": 128, "callbacks": [ EarlyStopping(monitor="val_loss", patience=3) ], "series_val": data_val, }, ) forecaster

Out[39]:

============= 
ForecasterRnn 
============= 
Regressor: <keras.src.engine.functional.Functional object at 0x7f49a04966d0> 
Lags: [ 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
 25 26 27 28 29 30 31 32] 
Transformer for series: MinMaxScaler() 
Window size: 32 
Target series, levels: ['pm2.5', 'co', 'no', 'o3'] 
Multivariate series (names): None 
Maximum steps predicted: [1 2 3 4 5] 
Training range: None 
Training index type: None 
Training index frequency: None 
Model parameters: {'name': 'model_3', 'trainable': True, 'layers': [{'module': 'keras.layers', 'class_name': 'InputLayer', 'config': {'batch_input_shape': (None, 32, 10), 'dtype': 'float32', 'sparse': False, 'ragged': False, 'name': 'input_4'}, 'registered_name': None, 'name': 'input_4', 'inbound_nodes': []}, {'module': 'keras.layers', 'class_name': 'LSTM', 'config': {'name': 'lstm_4', 'trainable': True, 'dtype': 'float32', 'return_sequences': True, 'return_state': False, 'go_backwards': False, 'stateful': False, 'unroll': False, 'time_major': False, 'units': 100, 'activation': 'relu', 'recurrent_activation': 'sigmoid', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'recurrent_initializer': {'module': 'keras.initializers', 'class_name': 'Orthogonal', 'config': {'gain': 1.0, 'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'unit_forget_bias': True, 'kernel_regularizer': None, 'recurrent_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'recurrent_constraint': None, 'bias_constraint': None, 'dropout': 0.0, 'recurrent_dropout': 0.0, 'implementation': 2}, 'registered_name': None, 'build_config': {'input_shape': (None, 32, 10)}, 'name': 'lstm_4', 'inbound_nodes': [[['input_4', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'LSTM', 'config': {'name': 'lstm_5', 'trainable': True, 'dtype': 'float32', 'return_sequences': False, 'return_state': False, 'go_backwards': False, 'stateful': False, 'unroll': False, 'time_major': False, 'units': 50, 'activation': 'relu', 'recurrent_activation': 'sigmoid', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'recurrent_initializer': {'module': 'keras.initializers', 'class_name': 'Orthogonal', 'config': {'gain': 1.0, 'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'unit_forget_bias': True, 'kernel_regularizer': None, 'recurrent_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'recurrent_constraint': None, 'bias_constraint': None, 'dropout': 0.0, 'recurrent_dropout': 0.0, 'implementation': 2}, 'registered_name': None, 'build_config': {'input_shape': (None, 32, 100)}, 'name': 'lstm_5', 'inbound_nodes': [[['lstm_4', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_7', 'trainable': True, 'dtype': 'float32', 'units': 64, 'activation': 'relu', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 50)}, 'name': 'dense_7', 'inbound_nodes': [[['lstm_5', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_8', 'trainable': True, 'dtype': 'float32', 'units': 32, 'activation': 'relu', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 64)}, 'name': 'dense_8', 'inbound_nodes': [[['dense_7', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_9', 'trainable': True, 'dtype': 'float32', 'units': 20, 'activation': 'linear', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 32)}, 'name': 'dense_9', 'inbound_nodes': [[['dense_8', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Reshape', 'config': {'name': 'reshape_3', 'trainable': True, 'dtype': 'float32', 'target_shape': (5, 4)}, 'registered_name': None, 'build_config': {'input_shape': (None, 20)}, 'name': 'reshape_3', 'inbound_nodes': [[['dense_9', 0, 0, {}]]]}], 'input_layers': [['input_4', 0, 0]], 'output_layers': [['reshape_3', 0, 0]]} 
Compile parameters: {'optimizer': {'module': 'keras.optimizers', 'class_name': 'Adam', 'config': {'name': 'Adam', 'weight_decay': None, 'clipnorm': None, 'global_clipnorm': None, 'clipvalue': None, 'use_ema': False, 'ema_momentum': 0.99, 'ema_overwrite_frequency': None, 'jit_compile': False, 'is_legacy_optimizer': False, 'learning_rate': 0.009999999776482582, 'beta_1': 0.9, 'beta_2': 0.999, 'epsilon': 1e-07, 'amsgrad': False}, 'registered_name': None}, 'loss': {'module': 'keras.losses', 'class_name': 'MeanSquaredError', 'config': {'reduction': 'auto', 'name': 'mean_squared_error', 'fn': 'mean_squared_error'}, 'registered_name': None}, 'metrics': None, 'loss_weights': None, 'weighted_metrics': None, 'run_eagerly': None, 'steps_per_execution': None, 'jit_compile': None} 
fit_kwargs: {'epochs': 10, 'batch_size': 128, 'callbacks': [<keras.src.callbacks.EarlyStopping object at 0x7f49a2b65c10>]} 
Creation date: 2024-05-05 13:17:08 
Last fit date: None 
Skforecast version: 0.12.0 
Python version: 3.11.8 
Forecaster id: None 

In [40]:

# Fit forecaster
# ==============================================================================
forecaster.fit(data_train)

# Fit forecaster # ============================================================================== forecaster.fit(data_train)

Epoch 1/10
154/154 [==============================] - 16s 85ms/step - loss: 0.0084 - val_loss: 0.0098
Epoch 2/10
154/154 [==============================] - 13s 82ms/step - loss: 0.0046 - val_loss: 0.0089
Epoch 3/10
154/154 [==============================] - 13s 82ms/step - loss: 0.0041 - val_loss: 0.0086
Epoch 4/10
154/154 [==============================] - 13s 82ms/step - loss: 0.0039 - val_loss: 0.0074
Epoch 5/10
154/154 [==============================] - 13s 83ms/step - loss: 0.0036 - val_loss: 0.0073
Epoch 6/10
154/154 [==============================] - 13s 83ms/step - loss: 0.0034 - val_loss: 0.0071
Epoch 7/10
154/154 [==============================] - 13s 83ms/step - loss: 0.0034 - val_loss: 0.0073
Epoch 8/10
154/154 [==============================] - 13s 83ms/step - loss: 0.0033 - val_loss: 0.0073
Epoch 9/10
154/154 [==============================] - 13s 84ms/step - loss: 0.0032 - val_loss: 0.0076

The prediction can also be made for specific steps, as long as they are within the prediction horizon defined in the model.

In [41]:

# Specific step predictions
# ==============================================================================
forecaster.predict(steps=[1, 5], levels="o3")

# Specific step predictions # ============================================================================== forecaster.predict(steps=[1, 5], levels="o3")

Out[41]:

	o3
2021-04-01 00:00:00	25.718916
2021-04-01 04:00:00	18.777706

In [42]:

# Prediction
# ==============================================================================
predictions = forecaster.predict()
predictions

# Prediction # ============================================================================== predictions = forecaster.predict() predictions

Out[42]:

	pm2.5	co	no	o3
2021-04-01 00:00:00	13.276034	0.121996	3.038680	25.718916
2021-04-01 01:00:00	12.844429	0.117681	1.579634	24.361898
2021-04-01 02:00:00	12.150990	0.116040	1.216757	23.933695
2021-04-01 03:00:00	11.678197	0.119423	0.991251	22.380939
2021-04-01 04:00:00	11.605866	0.119320	1.395777	18.777706

In [43]:

# Backtesting with test data
# ==============================================================================
metrics, predictions = backtesting_forecaster_multiseries(
    forecaster=forecaster,
    steps=forecaster.max_step,
    series=data,
    levels=forecaster.levels,
    initial_train_size=len(data.loc[:end_validation, :]),
    metric="mean_absolute_error",
    verbose=False,
    refit=False,
)

# Backtesting with test data # ============================================================================== metrics, predictions = backtesting_forecaster_multiseries( forecaster=forecaster, steps=forecaster.max_step, series=data, levels=forecaster.levels, initial_train_size=len(data.loc[:end_validation, :]), metric="mean_absolute_error", verbose=False, refit=False, )

Epoch 1/10
188/188 [==============================] - 18s 84ms/step - loss: 0.0032 - val_loss: 0.0071
Epoch 2/10
188/188 [==============================] - 15s 81ms/step - loss: 0.0031 - val_loss: 0.0070
Epoch 3/10
188/188 [==============================] - 15s 81ms/step - loss: 0.0030 - val_loss: 0.0067
Epoch 4/10
188/188 [==============================] - 15s 81ms/step - loss: 0.0030 - val_loss: 0.0071
Epoch 5/10
188/188 [==============================] - 15s 81ms/step - loss: 0.0030 - val_loss: 0.0071
Epoch 6/10
188/188 [==============================] - 15s 81ms/step - loss: 0.0030 - val_loss: 0.0071

  0%|          | 0/442 [00:00<?, ?it/s]

In [44]:

# Backtesting metrics
# ==============================================================================
metrics

# Backtesting metrics # ============================================================================== metrics

Out[44]:

	levels	mean_absolute_error
0	pm2.5	4.008601
1	co	0.026727
2	no	2.917722
3	o3	11.916396

In [45]:

# Plot all the predicted variables as rows in the plot
# ==============================================================================
fig, ax = plt.subplots(len(levels), 1, figsize=(8, 3*len(levels)), sharex=True)
for i, level in enumerate(levels):
    data_test[level].plot(ax=ax[i], label="test")
    predictions[level].plot(ax=ax[i], label="predictions")
    ax[i].set_title(level)
    ax[i].legend()

# Plot all the predicted variables as rows in the plot # ============================================================================== fig, ax = plt.subplots(len(levels), 1, figsize=(8, 3*len(levels)), sharex=True) for i, level in enumerate(levels): data_test[level].plot(ax=ax[i], label="test") predictions[level].plot(ax=ax[i], label="predictions") ax[i].set_title(level) ax[i].legend()

Create and compile Tensorflow models¶

To improve the user experience and speed up the prototyping, development, and production process, skforecast has the create_and_compile_model function, with which, by indicating just a few arguments, the architecture is inferred and the model is created.

• series: Time series to be used to train the model

• levels: Time series to be predicted.

• lags: Number of time steps to be used to predict the next value.

• steps: Number of time steps to be predicted.

• recurrent_layer: Type of recurrent layer to use. By default, an LSTM layer is used.

• recurrent_units: Number of units in the recurrent layer. By default, 100 is used. If a list is passed, a recurrent layer will be created for each element in the list.

• dense_units: Number of units in the dense layer. By default, 64 is used. If a list is passed, a dense layer will be created for each element in the list.

• optimizer: Optimizer to use. By default, Adam with a learning rate of 0.01 is used.

• loss: Loss function to use. By default, Mean Squared Error is used.

  Note

The following examples use recurrent_layer="LSTM" but it is also possible to use "RNN" layers.

In [46]:

# Create model
# ==============================================================================
series = ["o3"] # Series used as predictors
levels = ["o3"] # Target series to predict
lags = 32 # Past time steps to be used to predict the target
steps = 1 # Future time steps to be predicted

data = air_quality[series].copy()
data_train = air_quality_train[series].copy()
data_val = air_quality_val[series].copy()
data_test = air_quality_test[series].copy()

model = create_and_compile_model(
    series=data_train,
    levels=levels, 
    lags=lags,
    steps=steps,
    recurrent_layer="LSTM",
    recurrent_units=4,
    dense_units=16,
    optimizer=Adam(learning_rate=0.01), 
    loss=MeanSquaredError()
)
model.summary()

# Create model # ============================================================================== series = ["o3"] # Series used as predictors levels = ["o3"] # Target series to predict lags = 32 # Past time steps to be used to predict the target steps = 1 # Future time steps to be predicted data = air_quality[series].copy() data_train = air_quality_train[series].copy() data_val = air_quality_val[series].copy() data_test = air_quality_test[series].copy() model = create_and_compile_model( series=data_train, levels=levels, lags=lags, steps=steps, recurrent_layer="LSTM", recurrent_units=4, dense_units=16, optimizer=Adam(learning_rate=0.01), loss=MeanSquaredError() ) model.summary()

Model: "model_4"
_________________________________________________________________
 Layer (type)                Output Shape              Param #   
=================================================================
 input_5 (InputLayer)        [(None, 32, 1)]           0         
                                                                 
 lstm_6 (LSTM)               (None, 4)                 96        
                                                                 
 dense_10 (Dense)            (None, 16)                80        
                                                                 
 dense_11 (Dense)            (None, 1)                 17        
                                                                 
 reshape_4 (Reshape)         (None, 1, 1)              0         
                                                                 
=================================================================
Total params: 193 (772.00 Byte)
Trainable params: 193 (772.00 Byte)
Non-trainable params: 0 (0.00 Byte)
_________________________________________________________________

In this case, a simple LSTM network is used, with a single recurrent layer with 4 neurons and a hidden dense layer with 16 neurons. The following table shows a detailed description of each layer:

Layer	Type	Output Shape	Parameters	Description
Input Layer (InputLayer)	InputLayer	(None, 32, 1)	0	This is the input layer of the model. It receives sequences of length 32, corresponding to the number of lags with a dimension at each time step.
LSTM Layer (Long Short-Term Memory)	LSTM	(None, 4)	96	The LSTM layer is a long and short-term memory layer that processes the input sequence. It has 4 LSTM units and connects to the next layer.
First Dense Layer (Dense)	Dense	(None, 16)	80	This is a fully connected layer with 16 units and uses a default activation function (relu) in the provided architecture.
Second Dense Layer (Dense)	Dense	(None, 1)	17	Another fully connected dense layer, this time with a single output unit. It also uses a default activation function.
Reshape Layer (Reshape)	Reshape	(None, 1, 1)	0	This layer reshapes the output of the previous dense layer to have a specific shape (None, 1, 1). This layer is not strictly necessary, but is included to make the module generalizable to other multi-output forecasting problems. The dimension of this output layer is (None, steps_to_predict_future, series_to_predict). In this case, steps=1 and levels="o3", so the dimension is (None, 1, 1)
Total Parameters and Trainable	-	-	193	Total Parameters: 193, Trainable Parameters: 193, Non-Trainable Parameters: 0

More complex models can be created including:

• Multiple series to be modeled (levels)
• Multiple series to be used as predictors (series)
• Multiple steps to be predicted (steps)
• Multiple lags to be used as predictors (lags)
• Multiple recurrent layers (recurrent_units)
• Multiple dense layers (dense_units)

In [47]:

# Model creation
# ==============================================================================
# Now, we have multiple series and multiple targets
series = ['pm2.5', 'co', 'no', 'no2', 'pm10', 'nox', 'o3', 'veloc.', 'direc.','so2'] 
levels = ['pm2.5', 'co', 'no', "o3"] #  Features to predict. It can be all the series or less
lags = 32 
steps = 5 

data = air_quality[series].copy()
data_train = air_quality_train[series].copy()
data_val = air_quality_val[series].copy()
data_test = air_quality_test[series].copy()

model = create_and_compile_model(
    series=data_train,
    levels=levels, 
    lags=lags,
    steps=steps,
    recurrent_layer="LSTM",
    recurrent_units=[100, 50],
    dense_units=[64, 32],
    optimizer=Adam(learning_rate=0.01), 
    loss=MeanSquaredError()
)
model.summary()

# Model creation # ============================================================================== # Now, we have multiple series and multiple targets series = ['pm2.5', 'co', 'no', 'no2', 'pm10', 'nox', 'o3', 'veloc.', 'direc.','so2'] levels = ['pm2.5', 'co', 'no', "o3"] # Features to predict. It can be all the series or less lags = 32 steps = 5 data = air_quality[series].copy() data_train = air_quality_train[series].copy() data_val = air_quality_val[series].copy() data_test = air_quality_test[series].copy() model = create_and_compile_model( series=data_train, levels=levels, lags=lags, steps=steps, recurrent_layer="LSTM", recurrent_units=[100, 50], dense_units=[64, 32], optimizer=Adam(learning_rate=0.01), loss=MeanSquaredError() ) model.summary()

Model: "model_5"
_________________________________________________________________
 Layer (type)                Output Shape              Param #   
=================================================================
 input_6 (InputLayer)        [(None, 32, 10)]          0         
                                                                 
 lstm_7 (LSTM)               (None, 32, 100)           44400     
                                                                 
 lstm_8 (LSTM)               (None, 50)                30200     
                                                                 
 dense_12 (Dense)            (None, 64)                3264      
                                                                 
 dense_13 (Dense)            (None, 32)                2080      
                                                                 
 dense_14 (Dense)            (None, 20)                660       
                                                                 
 reshape_5 (Reshape)         (None, 5, 4)              0         
                                                                 
=================================================================
Total params: 80604 (314.86 KB)
Trainable params: 80604 (314.86 KB)
Non-trainable params: 0 (0.00 Byte)
_________________________________________________________________

Get training and test matrices¶

In [12]:

# Model creation
# ==============================================================================
series = ['pm2.5', 'co', 'no', 'no2', 'pm10', 'nox', 'o3', 'veloc.', 'direc.','so2'] 
levels = ['pm2.5', 'co', 'no', "o3"] #  Features to predict. It can be all the series or less
lags = 10 
steps = 5 

data = air_quality[series].copy()
data_train = air_quality_train[series].copy()
data_val = air_quality_val[series].copy()
data_test = air_quality_test[series].copy()

model = create_and_compile_model(
    series=data_train,
    levels=levels, 
    lags=lags,
    steps=steps,
    recurrent_layer="LSTM",
    recurrent_units=[100, 50],
    dense_units=[64, 32],
    optimizer=Adam(learning_rate=0.01), 
    loss=MeanSquaredError()
)

forecaster = ForecasterRnn(
    regressor=model,
    levels=levels,
    steps=steps,
    lags=lags,
)
forecaster

# Model creation # ============================================================================== series = ['pm2.5', 'co', 'no', 'no2', 'pm10', 'nox', 'o3', 'veloc.', 'direc.','so2'] levels = ['pm2.5', 'co', 'no', "o3"] # Features to predict. It can be all the series or less lags = 10 steps = 5 data = air_quality[series].copy() data_train = air_quality_train[series].copy() data_val = air_quality_val[series].copy() data_test = air_quality_test[series].copy() model = create_and_compile_model( series=data_train, levels=levels, lags=lags, steps=steps, recurrent_layer="LSTM", recurrent_units=[100, 50], dense_units=[64, 32], optimizer=Adam(learning_rate=0.01), loss=MeanSquaredError() ) forecaster = ForecasterRnn( regressor=model, levels=levels, steps=steps, lags=lags, ) forecaster

Out[12]:

============= 
ForecasterRnn 
============= 
Regressor: <keras.src.engine.functional.Functional object at 0x141122110> 
Lags: [ 1  2  3  4  5  6  7  8  9 10] 
Transformer for series: MinMaxScaler() 
Window size: 10 
Target series, levels: ['pm2.5', 'co', 'no', 'o3'] 
Multivariate series (names): None 
Maximum steps predicted: [1 2 3 4 5] 
Training range: None 
Training index type: None 
Training index frequency: None 
Model parameters: {'name': 'model_1', 'trainable': True, 'layers': [{'module': 'keras.layers', 'class_name': 'InputLayer', 'config': {'batch_input_shape': (None, 10, 10), 'dtype': 'float32', 'sparse': False, 'ragged': False, 'name': 'input_2'}, 'registered_name': None, 'name': 'input_2', 'inbound_nodes': []}, {'module': 'keras.layers', 'class_name': 'LSTM', 'config': {'name': 'lstm_2', 'trainable': True, 'dtype': 'float32', 'return_sequences': True, 'return_state': False, 'go_backwards': False, 'stateful': False, 'unroll': False, 'time_major': False, 'units': 100, 'activation': 'relu', 'recurrent_activation': 'sigmoid', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'recurrent_initializer': {'module': 'keras.initializers', 'class_name': 'Orthogonal', 'config': {'gain': 1.0, 'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'unit_forget_bias': True, 'kernel_regularizer': None, 'recurrent_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'recurrent_constraint': None, 'bias_constraint': None, 'dropout': 0.0, 'recurrent_dropout': 0.0, 'implementation': 2}, 'registered_name': None, 'build_config': {'input_shape': (None, 10, 10)}, 'name': 'lstm_2', 'inbound_nodes': [[['input_2', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'LSTM', 'config': {'name': 'lstm_3', 'trainable': True, 'dtype': 'float32', 'return_sequences': False, 'return_state': False, 'go_backwards': False, 'stateful': False, 'unroll': False, 'time_major': False, 'units': 50, 'activation': 'relu', 'recurrent_activation': 'sigmoid', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'recurrent_initializer': {'module': 'keras.initializers', 'class_name': 'Orthogonal', 'config': {'gain': 1.0, 'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'unit_forget_bias': True, 'kernel_regularizer': None, 'recurrent_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'recurrent_constraint': None, 'bias_constraint': None, 'dropout': 0.0, 'recurrent_dropout': 0.0, 'implementation': 2}, 'registered_name': None, 'build_config': {'input_shape': (None, 10, 100)}, 'name': 'lstm_3', 'inbound_nodes': [[['lstm_2', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_3', 'trainable': True, 'dtype': 'float32', 'units': 64, 'activation': 'relu', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 50)}, 'name': 'dense_3', 'inbound_nodes': [[['lstm_3', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_4', 'trainable': True, 'dtype': 'float32', 'units': 32, 'activation': 'relu', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 64)}, 'name': 'dense_4', 'inbound_nodes': [[['dense_3', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Dense', 'config': {'name': 'dense_5', 'trainable': True, 'dtype': 'float32', 'units': 20, 'activation': 'linear', 'use_bias': True, 'kernel_initializer': {'module': 'keras.initializers', 'class_name': 'GlorotUniform', 'config': {'seed': None}, 'registered_name': None}, 'bias_initializer': {'module': 'keras.initializers', 'class_name': 'Zeros', 'config': {}, 'registered_name': None}, 'kernel_regularizer': None, 'bias_regularizer': None, 'activity_regularizer': None, 'kernel_constraint': None, 'bias_constraint': None}, 'registered_name': None, 'build_config': {'input_shape': (None, 32)}, 'name': 'dense_5', 'inbound_nodes': [[['dense_4', 0, 0, {}]]]}, {'module': 'keras.layers', 'class_name': 'Reshape', 'config': {'name': 'reshape_1', 'trainable': True, 'dtype': 'float32', 'target_shape': (5, 4)}, 'registered_name': None, 'build_config': {'input_shape': (None, 20)}, 'name': 'reshape_1', 'inbound_nodes': [[['dense_5', 0, 0, {}]]]}], 'input_layers': [['input_2', 0, 0]], 'output_layers': [['reshape_1', 0, 0]]} 
Compile parameters: {'optimizer': {'module': 'keras.optimizers', 'class_name': 'Adam', 'config': {'name': 'Adam', 'weight_decay': None, 'clipnorm': None, 'global_clipnorm': None, 'clipvalue': None, 'use_ema': False, 'ema_momentum': 0.99, 'ema_overwrite_frequency': None, 'jit_compile': False, 'is_legacy_optimizer': False, 'learning_rate': 0.009999999776482582, 'beta_1': 0.9, 'beta_2': 0.999, 'epsilon': 1e-07, 'amsgrad': False}, 'registered_name': None}, 'loss': {'module': 'keras.losses', 'class_name': 'MeanSquaredError', 'config': {'reduction': 'auto', 'name': 'mean_squared_error', 'fn': 'mean_squared_error'}, 'registered_name': None}, 'metrics': None, 'loss_weights': None, 'weighted_metrics': None, 'run_eagerly': None, 'steps_per_execution': None, 'jit_compile': None} 
fit_kwargs: {} 
Creation date: 2024-05-09 01:28:49 
Last fit date: None 
Skforecast version: 0.12.0 
Python version: 3.11.7 
Forecaster id: None 

In [13]:

forecaster.create_train_X_y(data_train)[2]["X_train"][2]

forecaster.create_train_X_y(data_train)[2]["X_train"][2]

Out[13]:

['pm2.5', 'co', 'no', 'no2', 'pm10', 'nox', 'o3', 'veloc.', 'direc.', 'so2']

The RNN Forecaster can also be used to generate the X_train and y_train matrices that will be used to train the model. The create_train_X_y method allows the user to obtain the training and test matrices that will be used to train the model. The method return 3 elements: X_train, y_train, and dimension_information. The X_train matrix has dimensions (n_samples, n_lags, n_series), while the y_train matrix has dimensions (n_samples, n_steps, n_levels).

In [14]:

X_train, y_train, dimension_info = forecaster.create_train_X_y(data_train)

X_train, y_train, dimension_info = forecaster.create_train_X_y(data_train)

In [15]:

X_train.shape, y_train.shape

X_train.shape, y_train.shape

Out[15]:

((19690, 10, 10), (19690, 5, 4))

The dimension_information dictionary contains the information of each dimension value for both X_train and y_train.

In [16]:

dimension_info["X_train"][0][:10]

dimension_info["X_train"][0][:10]

Out[16]:

[Timestamp('2019-01-01 10:00:00'),
 Timestamp('2019-01-01 11:00:00'),
 Timestamp('2019-01-01 12:00:00'),
 Timestamp('2019-01-01 13:00:00'),
 Timestamp('2019-01-01 14:00:00'),
 Timestamp('2019-01-01 15:00:00'),
 Timestamp('2019-01-01 16:00:00'),
 Timestamp('2019-01-01 17:00:00'),
 Timestamp('2019-01-01 18:00:00'),
 Timestamp('2019-01-01 19:00:00')]

In [17]:

dimension_info["X_train"][1]

dimension_info["X_train"][1]

Out[17]:

['lag_1',
 'lag_2',
 'lag_3',
 'lag_4',
 'lag_5',
 'lag_6',
 'lag_7',
 'lag_8',
 'lag_9',
 'lag_10']

In [18]:

dimension_info["X_train"][2]

dimension_info["X_train"][2]

Out[18]:

['pm2.5', 'co', 'no', 'no2', 'pm10', 'nox', 'o3', 'veloc.', 'direc.', 'so2']

In [19]:

dimension_info["y_train"][0][:10]

dimension_info["y_train"][0][:10]

Out[19]:

[Timestamp('2019-01-01 10:00:00'),
 Timestamp('2019-01-01 11:00:00'),
 Timestamp('2019-01-01 12:00:00'),
 Timestamp('2019-01-01 13:00:00'),
 Timestamp('2019-01-01 14:00:00'),
 Timestamp('2019-01-01 15:00:00'),
 Timestamp('2019-01-01 16:00:00'),
 Timestamp('2019-01-01 17:00:00'),
 Timestamp('2019-01-01 18:00:00'),
 Timestamp('2019-01-01 19:00:00')]

In [20]:

dimension_info["y_train"][1]

dimension_info["y_train"][1]

Out[20]:

['step_1', 'step_2', 'step_3', 'step_4', 'step_5']

In [21]:

dimension_info["y_train"][2]

dimension_info["y_train"][2]

Out[21]:

['pm2.5', 'co', 'no', 'o3']